I noticed that in the Strategikon it mentions that cavalry would carry their lances on the backs when it wasn't in use. How would the spear be held up against the soldier's back so it wouldn't fall off or move around? Did they have some sort of sheath or sling to hold it (like how you might hold a group of javelins), or is it something else entirely?

cmmcgarr wrote:I noticed that in the Strategikon it mentions that cavalry would carry their lances on the backs when it wasn't in use. How would the spear be held up against the soldier's back so it wouldn't fall off or move around? Did they have some sort of sheath or sling to hold it (like how you might hold a group of javelins), or is it something else entirely?

Dunno but much later lancers in the British army had a looped strap to go on the upper right arm and the butt of the lance fitted into a leather 'boot' attached to the right stirrup. Something like that perhaps?